X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/fa33c62c831c17237ac38960b24596560ad3804d..3f9b311ec56db95ec539001a860ae3c838c48312:/src/mc/explo/DFSExplorer.cpp diff --git a/src/mc/explo/DFSExplorer.cpp b/src/mc/explo/DFSExplorer.cpp index f82d8da149..b328d15773 100644 --- a/src/mc/explo/DFSExplorer.cpp +++ b/src/mc/explo/DFSExplorer.cpp @@ -8,8 +8,10 @@ #include "src/mc/mc_exit.hpp" #include "src/mc/mc_private.hpp" #include "src/mc/mc_record.hpp" +#include "src/mc/remote/mc_protocol.h" #include "src/mc/transition/Transition.hpp" +#include "xbt/asserts.h" #include "xbt/log.h" #include "xbt/string.hpp" #include "xbt/sysdep.h" @@ -65,12 +67,9 @@ void DFSExplorer::restore_stack(std::shared_ptr state) } XBT_DEBUG("Replaced stack by %s", get_record_trace().to_string().c_str()); if (reduction_mode_ == ReductionMode::sdpor || reduction_mode_ == ReductionMode::odpor) { - // NOTE: The outgoing transition for the top-most - // state of the stack refers to that which was taken - // as part of the last trace explored by the algorithm. - // Thus, only the sequence of transitions leading up to, - // but not including, the last state must be included - // when reconstructing the Exploration for SDPOR. + // NOTE: The outgoing transition for the top-most state of the stack refers to that which was taken + // as part of the last trace explored by the algorithm. Thus, only the sequence of transitions leading up to, + // but not including, the last state must be included when reconstructing the Exploration for SDPOR. for (auto iter = std::next(stack_.begin()); iter != stack_.end(); ++iter) { execution_seq_.push_transition((*iter)->get_transition_in()); } @@ -124,16 +123,12 @@ void DFSExplorer::run() } if (reduction_mode_ == ReductionMode::odpor) { - // In the case of ODPOR, the wakeup tree for this - // state may be empty if we're exploring new territory - // (rather than following the partial execution of a - // wakeup tree). This corresponds to lines 9 to 13 of + // In the case of ODPOR, the wakeup tree for this state may be empty if we're exploring new territory + // (rather than following the partial execution of a wakeup tree). This corresponds to lines 9 to 13 of // the ODPOR pseudocode // - // INVARIANT: The execution sequence should be consistent - // with the state when seeding the tree. If the sequence - // gets out of sync with the state, selection will not - // work as we intend + // INVARIANT: The execution sequence should be consistent with the state when seeding the tree. If the sequence + // gets out of sync with the state, selection will not work as we intend state->seed_wakeup_tree_if_needed(execution_seq_); } @@ -143,7 +138,21 @@ void DFSExplorer::run() const aid_t next = reduction_mode_ == ReductionMode::odpor ? state->next_odpor_transition() : std::get<0>(state->next_transition_guided()); - if (next < 0) { // If there is no more transition in the current state, backtrack. + if (next < 0 || not state->is_actor_enabled(next)) { + if (next >= 0) { // Actor is not enabled, then + XBT_DEBUG( + "Reduction %s wants to execute a disabled transition %s. If it's ODPOR, ReversibleRace is suboptimal.", + to_c_str(reduction_mode_), state->get_actors_list().at(next).get_transition()->to_string(true).c_str()); + if (reduction_mode_ == ReductionMode::odpor) { + // Remove the disabled transition from the wakeup tree so that ODPOR doesn't try it again + state->remove_subtree_at_aid(next); + state->add_sleep_set(state->get_actors_list().at(next).get_transition()); + } else { + xbt_assert(false, "Only ODPOR should be confident enought in itself to try executing a disabled transition"); + } + } + // If there is no more transition in the current state (or if ODPOR picked an actor that is not enabled -- + // ReversibleRace is an overapproximation), backtrace XBT_VERB("%lu actors remain, but none of them need to be interleaved (depth %zu).", state->get_actor_count(), stack_.size() + 1); @@ -163,13 +172,16 @@ void DFSExplorer::run() XBT_VERB(" <%ld,%s>", aid, transition->to_string().c_str()); } + auto todo = state->get_actors_list().at(next).get_transition(); + XBT_DEBUG("wanna execute %ld: %.60s", next, todo->to_string().c_str()); + /* Actually answer the request: let's execute the selected request (MCed does one step) */ auto executed_transition = state->execute_next(next, get_remote_app()); on_transition_execute_signal(state->get_transition_out().get(), get_remote_app()); // If there are processes to interleave and the maximum depth has not been // reached then perform one step of the exploration algorithm. - XBT_VERB("Execute %ld: %.150s (stack depth: %zu, state: %ld, %zu interleaves)", state->get_transition_out()->aid_, + XBT_VERB("Executed %ld: %.60s (stack depth: %zu, state: %ld, %zu interleaves)", state->get_transition_out()->aid_, state->get_transition_out()->to_string().c_str(), stack_.size(), state->get_num(), state->count_todo()); /* Create the new expanded state (copy the state of MCed into our MCer data) */ @@ -177,13 +189,10 @@ void DFSExplorer::run() on_state_creation_signal(next_state.get(), get_remote_app()); if (reduction_mode_ == ReductionMode::odpor) { - // With ODPOR, after taking a step forward, we must - // assign a copy of that subtree to the next state. + // With ODPOR, after taking a step forward, we must assign a copy of that subtree to the next state. // - // NOTE: We only add actions to the sleep set AFTER - // we've regenerated states. We must perform the search - // fully down a single path before we consider adding - // any elements to the sleep set according to the pseudocode + // NOTE: We only add actions to the sleep set AFTER we've regenerated states. We must perform the search + // fully down a single path before we consider adding any elements to the sleep set according to the pseudocode next_state->sprout_tree_from_parent_state(); } else { /* Sleep set procedure: @@ -245,15 +254,13 @@ void DFSExplorer::run() /** * SDPOR Source Set Procedure: * - * Find "reversible races" in the current execution `E` with respect - * to the latest action `p`. For each such race, determine one thread - * not contained in the backtrack set at the "race point" `r` which - * "represents" the trace formed by first executing everything after - * `r` that doesn't depend on it (`v := notdep(r, E)`) and then `p` to + * Find "reversible races" in the current execution `E` with respect to the latest action `p`. For each such race, + * determine one thread not contained in the backtrack set at the "race point" `r` which "represents" the trace + * formed by first executing everything after `r` that doesn't depend on it (`v := notdep(r, E)`) and then `p` to * flip the race. * - * The intuition is that some subsequence of `v` may enable `p`, so - * we want to be sure that search "in that direction" + * The intuition is that some subsequence of `v` may enable `p`, so we want to be sure that search "in that + * direction" */ execution_seq_.push_transition(std::move(executed_transition)); xbt_assert(execution_seq_.get_latest_event_handle().has_value(), "No events are contained in the SDPOR execution " @@ -264,12 +271,10 @@ void DFSExplorer::run() State* prev_state = stack_[e_race].get(); const auto choices = execution_seq_.get_missing_source_set_actors_from(e_race, prev_state->get_backtrack_set()); if (not choices.empty()) { - // NOTE: To incorporate the idea of attempting to select the "best" - // backtrack point into SDPOR, instead of selecting the `first` initial, - // we should instead compute all choices and decide which is best + // NOTE: To incorporate the idea of attempting to select the "best" backtrack point into SDPOR, instead of + // selecting the `first` initial, we should instead compute all choices and decide which is best // - // Here, we choose the actor with the lowest ID to ensure - // we get deterministic results + // Here, we choose the actor with the lowest ID to ensure we get deterministic results const auto q = std::min_element(choices.begin(), choices.end(), [](const aid_t a1, const aid_t a2) { return a1 < a2; }); prev_state->consider_one(*q); @@ -277,8 +282,7 @@ void DFSExplorer::run() } } } else if (reduction_mode_ == ReductionMode::odpor) { - // In the case of ODPOR, we simply observe the transition that was executed - // until we've reached a maximal trace + // In the case of ODPOR, we simply observe the transition that was executed until we've reached a maximal trace execution_seq_.push_transition(std::move(executed_transition)); } @@ -347,8 +351,6 @@ std::shared_ptr DFSExplorer::next_odpor_state() for (const auto& [aid, transition] : state->get_sleep_set()) XBT_DEBUG("\t <%ld,%s>", aid, transition->to_string().c_str()); if (not state->has_empty_tree()) { - XBT_DEBUG("\t found the following non-empty WuT:\n" - "%s", state->string_of_wut().c_str()); return state; } } @@ -362,15 +364,13 @@ void DFSExplorer::backtrack() /** * ODPOR Race Detection Procedure: * - * For each reversible race in the current execution, we - * note if there are any continuations `C` equivalent to that which - * would reverse the race that have already either a) been searched by ODPOR or - * b) been *noted* to be searched by the wakeup tree at the - * appropriate reversal point, either as `C` directly or - * an as equivalent to `C` ("eventually looks like C", viz. the `~_E` - * relation) + * For each reversible race in the current execution, we note if there are any continuations `C` equivalent to that + * which would reverse the race that have already either a) been searched by ODPOR or b) been *noted* to be searched + * by the wakeup tree at the appropriate reversal point, either as `C` directly or an as equivalent to `C` + * ("eventually looks like C", viz. the `~_E` relation) */ for (auto e_prime = static_cast(0); e_prime <= last_event.value(); ++e_prime) { + XBT_DEBUG("ODPOR: Now considering all possible race with `%u`", e_prime); for (const auto e : execution_seq_.get_reversible_races_of(e_prime)) { XBT_DEBUG("ODPOR: Reversible race detected between events `%u` and `%u`", e, e_prime); State& prev_state = *stack_[e]; @@ -433,7 +433,7 @@ void DFSExplorer::backtrack() // Search how to restore the backtracking point std::deque replay_recipe; - for (auto* s = backtracking_point.get(); s != nullptr; s = s->get_parent_state().get()) { + for (const auto* s = backtracking_point.get(); s != nullptr; s = s->get_parent_state().get()) { if (s->get_transition_in() != nullptr) // The root has no transition_in replay_recipe.push_front(s->get_transition_in().get()); }